SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afb67cf6d2c762778ebb9e6635fca24c85304aca098bc2f04dbe8cb20ead0d95' 
  AND token = 'viRb2sWn1Thyfis8Jr7VNI/0ia1VrmcRqerXk+OeeQ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}